Bike Forums

Bike Forums (
-   Mountain Biking (
-   -   Bottom bracket problem (

JimmyDean012 03-27-07 11:02 AM

Bottom bracket problem
I don't know what happened, but I was riding today through some muddy areas on a dirt road, and when I stood up to crank it, something in the bottom bracket slipped. It felt almost like the bike jumping gears, but it was like something just gave. The bike still works almost fine, but the crank arms have some play in them now, and on the down stroke of the left crank there is a bad creaking noise. Can you slip a bearing in a bottom bracket? How do I take this thing apart to diagnose/fix it? It was the only bearing I didn't repack as I have no clue how they go together. Thanks for your help.

Flak 03-27-07 11:40 AM

You might have just worked a crank arm loose, but servicing your BB is really very easy, and most bikes (not all) have cartridge bb's these days so theres no need to repack anything. Parktool/repair will see you through well enough.

JimmyDean012 03-27-07 06:49 PM

Well, the crank arm was lose. Really loose. That fixed the creaking on the down stroke, but there is still some play in the bottom bracket.

In other news, I switched out the brake levers, grip shifters, and brakes from my old bike. The Altus Cantilevers weren't working for crap (mostly due to the yoke plastic piece being trashed and pads being completely hard from the sun), and linear pull brakes have better mechanical advantage anyway. Only problem is, even with the cable tight and barrel adjuster to the max, it simply doesn't put the pad into the rim as hard as I'd like. Guess I'm going to have to shim the pad a little differently. The brakes are much better now than they were though, and that's good because hauling ass on this bike can be scary without brakes.

Flak 03-27-07 07:45 PM

If you rode the bike with a loose crankarm, you may have killed the BB. You really dont have to ride far with a loose arm to ruin your BB. Tighten the crap out of it, and if theres still play, i think it's a goner. Take it to your LBS to have them confirm this first though.

boss_stomper 03-21-08 02:17 PM

hows this one for unlcky then.....i just bought a cheapy from the catologue just to get me by, the first time i used it and the crank slips when under max pressure (granny gear up steap muddy hill covered in leaves) and bang, it felt like my chain skipped a couple of teeth but everything looked fine. when i got home i checked everything was tight and seemed ik so i took it out on the street and it makes funny kinda grinding nioses!!have i killed a brand new bb/crank?

All times are GMT -6. The time now is 09:52 PM.

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.